def alphabeta(r):
	if not isinstance(r,int):
		raise TypeError('Parameter should be int')
	if r>17576 or r<0:
		raise Exception('Parameter should between 0~17576')

	for i in range(r):

		if int(i/676)>=1:
			print (chr(int(i/676)+65)+chr(int((i%676)/26)+65)+chr((i)%26+65))
		elif int(i/26)>=1:
			print (chr(int(i/26)+65)+chr((i)%26+65))
		else:
			print (chr(i+65))


x=''
def iter(i,s):
	if i>26:
		s+=chr(int(i%26)+65)
		#print(s)
		#print(str(int(i%10)))
		#print(r,int(i/26),c)
		return iter(int(i/26),s)
	else:
		s+=chr(int(i%26)+65)
		return s[::-1]
		#print(str(int(i%10)))

